<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="style.css">
    <style>
        .all{
            width:100%;
            height: 200px;
            background: pink;
        }
        .all>div{
            width:50%;
            float:left;
            padding-right: 20px;
            /* width:calc(50% - 20px) */
            box-sizing: border-box;
        }
        .all>div img{
            width:100%;
            height:200px;
            border: solid 3px red;
            box-sizing: border-box;
        }
    </style>
</head>
<body>
   <div class="all">
       <div><img src="../day16/images/sky.jpg" alt=""></div>
       <div><img src="../day16/images/sky.jpg" alt=""></div>
   </div> 
</body>
</html>